The police watchdog is investigating claims a Surrey police officer leaked information about the Milly Dowler murder investigation to the News Of The World.

Milly Dowler, 13, was abducted and killed in Surrey in 2002

The Independent Police Complaints Commission (IPCC) said it had received a "voluntary referral" from the force about the allegation.

In a statement, the body said an IPCC deputy senior investigator had been at Surrey Police to get more information about the case.

"(The IPCC) will be writing to the Dowler family, via their solicitors at their request, this afternoon and offering to meet to give them more detail," it said.

"Until then it would not be appropriate for us to make any further detail public."

A spokeswoman for News International would not comment on the case but in a statement said that they were co-operating fully with the Met's "investigation into illegal voicemail interception and related issues at the News Of The World".

The Dowler family welcome the full investigation into what happened at the time of the initial inquiry into Milly's disappearance.

Mark Lewis, the Dowler family's lawyer

It is the latest development amid the police investigation into the phone hacking scandal and follows reports 13-year-old Milly's mobile phone was hacked by a private detective working for the tabloid newspaper after she disappeared in 2002.

It also comes just weeks after revelations that a detective was removed from the case for leaking information.

Last month, Surrey Police confirmed the unnamed officer was "given words of advice" and permanently taken off the probe in 2002 for telling a friend, a retired police officer, details about the investigation.

The 13-year-old schoolgirl's family following the court case of her killer

Mark Lewis, the Dowler family's lawyer, said: "The Dowler family welcome the full investigation into what happened at the time of the initial inquiry into Milly's disappearance.

"It would not be appropriate to make any further comment at this stage."

Milly went missing as she was walking home from school after leaving Walton-on-Thames station in Surrey.

Convicted killer Levi Bellfield was later found quilty of the schoolgirl's abduction and murder.